Accuracy and Safety of Navigated Pedicle Screw Insertion in Cervical Spine Fractures

Jalal Mirzamohammadi¹Tor Arnøy Austad¹Vidar Stenset¹Donata Biernat¹Mads Aarhus^1,2Eirik Helseth^1,2*Hege Linnerud¹

• ¹Oslo University Hospital, Oslo, Norway
• ²Universitetet i Oslo, Oslo, Norway

Background: Pedicle screw (PS) fixation provides superior biomechanical stability compared with lateral mass screw (LMS) fixation for unstable cervical spine fractures (CS-Fx) but is associated with a risk of neurovascular injury. Navigation systems have improved PS placement accuracy, although most published studies remain small and underpowered to assess rare complications. Objective: To evaluate the accuracy and safety of navigation-assisted PS fixation for unstable CS-Fx in a population-based cohort. Methods: All consecutive patients with unstable CS-Fx who underwent navigated PS fixation at Oslo University Hospital between 2015 and 2024 were included in this study. Navigation was performed using preoperative CT-based surface matching. Postoperative CT scans obtained within 24 hours were used to grade PS accuracy as Grade 1 (<2 mm breach), Grade 2 (2–4 mm), or Grade 3 (>4 mm). Complications related to PS placement were recorded. Results: A total of 345 patients (median age 68 years; 75% males) underwent fixation with 1,347 navigated PSs. Screw accuracy was Grade 1 in 90% of cases, Grade 2 in 8% of cases, and Grade 3 in 2% of cases. Surgery-related complications occurred in 23 patients (6.7%), of whom 11 experienced complications directly related to PS placement. The per-screw complication risk was 0.8%, increasing with decreasing accuracy: 0.1% (Grade 1), 6% (Grade 2), and 14% (Grade 3). Vertebral artery injury occurred in seven patients; two patients experienced new-onset nerve root injury, one had a misplaced screw breaching the atlanto-occipital joint, and one developed significant perioperative bleeding. No cases of new-onset spinal cord injury or screw pull-out were observed. Surgical site infections occurred in 3.5% of patients and were successfully treated with debridement and antibiotics in all cases, without the need for implant removal. Conclusion: Navigated cervical PS fixation is accurate and associated with a low rate of serious complications. Meticulous planning and surgical technique remain essential despite the use of navigation assistance.